Let the wailing, hair-tearing and gnashing of teeth begin. Let Green Party leader Elizabeth May be fitted with her prison smock.

But also, let there be no mistake: It was inevitable Prime Minister Justin Trudeau would approve the $6.8-billion expansion of Kinder Morgan’s Trans Mountain pipeline. This was the only rational move available to him – and has been telegraphed as such, not for months, but years. Anyone voicing shock and indignation is either faking it, or hasn’t been paying attention.

In the aftermath of Tuesday’s news – Trudeau approved two major oil pipeline projects, Trans Mountain and Enbridge Line 3, and killed a third, Northern Gateway – the ululating have been severe. Various New Democrats, including B.C. MPs Peter Julian and Nathan Cullen, are outraged. Ms. May has vowed she’ll go to jail, presumably following some prosecutable act of civil disobedience, such as chaining herself to an oil barge.

Pundits have hemmed and hawed about the terrible quandary of Trudeau’s position and the dire straits into which he has thrust his party in southern B.C., where opposition to Trans Mountain has been vocal and will continue to be.

In fact it was never a quandary. Trudeau has been systematically laying the groundwork for this for better than four years – since his first campaign stop in Calgary, on day two of his leadership run. No country would find 173 billion barrels of oil in the ground and leave it there, he said back then – and repeated it Tuesday, virtually verbatim.

In October of 2013, in a speech to the Calgary Petroleum Club, Trudeau elaborated on the theme. After castigating Stephen Harper’s Conservatives for their failure to persuade the Obama administration to approve TransCanada’s Keystone XL project, which would transport Alberta oil to the Gulf Coast, he sketched the approach he’d take, given power.

“We need to open markets to our resources and facilitate the creation of pathways to those markets in responsible, sustainable ways,” he said, later adding: “Part and parcel of that strategy ought to be a national approach to pipelines and development, within an overall framework that puts a price on carbon…”

When Trudeau gave that speech, which he returned to time and time again including in last year’s election campaign, did all those now branding him a traitor to the environmentalist movement think he was kidding?

Oil is Canada’s most important commodity, constituting 20 per cent of the annual worth of our exports, underpinning the value of our dollar and our national wealth. Because so much of what we produce is landlocked, much of it now trades at a steep discount, upwards of 25 per cent, to the global price.

That translates into billions less in annual revenue for federal and provincial treasuries, which means that much less for social programs, or that much more in debt. It is arithmetic even the federal NDP – as distinct from Premier Rachel Notley’s Alberta NDP, now a very different party with diametrically opposing values, using the same name – and Greens should be able to grasp.

THE CANADIAN PRESS/Sean Kilpatrick

Is there a responsible, sustainable pathway for moving Canadian oil to global markets that is not a pipeline to the ocean? Failing the invention of industrial teleportation, not really. Is there a less invasive way to do it than by twinning or replacing and bulking up existing lines? No. But perhaps Trudeau was speaking in riddles and allegory all those times over many years he said he’d do what he just did.

Here’s why the Liberal claim this was done with political considerations aside should not immediately be met with hoots of laughter. Of course it was political: Every move any leader makes is, and the maneuvering that got the government here, including its climate dance with the provinces, has been politics of the most delicate sort.

But it is fair to say Trudeau and his senior team had more in mind than pipeline politics in making the decision. Their over-arching goal – again, since 2012, when winning power was still just a gleam in chief strategist Gerald Butts’ eye – has been to foster conditions for middle-class and working-class job growth, at a living wage. That is the alpha and omega of Justin Trudeau’s prime minister-ship and the measure by which he has said he wants to be judged.

Short of everyone working in the public service, as a teacher, cop or nurse, that means expanding the resource sector. Kinder Morgan expects to generate 15,000 jobs in the Trans Mountain construction phase alone, and the equivalent of 37,000 spinoff jobs after that. Not to mention the enormous economic benefits for Alberta and also for Ontario, which contributes significantly to the oil patch supply chain.

A pipeline westward is more important than a pipeline eastward, because the behemoth of potential new energy markets is China. Trans Mountain is thus the queen on this Liberal government’s game board – and any backing down or backing away, not in the cards. Elizabeth May, we pray, will get a cell with a window.